diff --git a/src/backend/browser/fileImpl.ts b/src/backend/browser/fileImpl.ts
index d60f85f30f..0dab45ac29 100644
--- a/src/backend/browser/fileImpl.ts
+++ b/src/backend/browser/fileImpl.ts
@@ -4,6 +4,7 @@ import { openDB } from "./browserConfig";
 import { SandboxKey } from "@/type/preload";
 import { failure, success } from "@/type/result";
 import { createLogger } from "@/domain/frontend/log";
+import { uuid4 } from "@/helpers/random";
 
 const log = createLogger("fileImpl");
 
@@ -200,7 +201,7 @@ export const showOpenFilePickerImpl = async (options: {
     });
     const paths = [];
     for (const handle of handles) {
-      const fakePath = `<browser-dummy-${crypto.randomUUID()}>-${handle.name}`;
+      const fakePath = `<browser-dummy-${uuid4()}>-${handle.name}`;
       fileHandleMap.set(fakePath, handle);
       paths.push(fakePath);
     }
diff --git a/src/components/Sing/ScoreSequencer.vue b/src/components/Sing/ScoreSequencer.vue
index 5a8a3c6514..a3717121ab 100644
--- a/src/components/Sing/ScoreSequencer.vue
+++ b/src/components/Sing/ScoreSequencer.vue
@@ -193,6 +193,7 @@ import {
 import { applyGaussianFilter, linearInterpolation } from "@/sing/utility";
 import { useLyricInput } from "@/composables/useLyricInput";
 import { ExhaustiveError } from "@/type/utility";
+import { uuid4 } from "@/helpers/random";
 
 type PreviewMode =
   | "ADD_NOTE"
@@ -720,7 +721,7 @@ const startPreview = (event: MouseEvent, mode: PreviewMode, note?: Note) => {
         return;
       }
       note = {
-        id: NoteId(crypto.randomUUID()),
+        id: NoteId(uuid4()),
         position: guideLineTicks,
         duration: snapTicks.value,
         noteNumber: cursorNoteNumber,
diff --git a/src/helpers/random.ts b/src/helpers/random.ts
new file mode 100644
index 0000000000..62e41e1ca1
--- /dev/null
+++ b/src/helpers/random.ts
@@ -0,0 +1,27 @@
+/**
+ * 乱数値を生成する。モックに対応している。
+ * モックモードでは呼ばれた回数に応じて固定の値を返す。
+ */
+
+let mockMode = false;
+let mockCount = 0;
+
+/**
+ * モックモードにし、呼ばれた回数をリセットする。
+ */
+export function resetMockMode(): void {
+  mockMode = true;
+  mockCount = 0;
+}
+
+/**
+ * v4 UUID を生成する。
+ */
+export function uuid4(): string {
+  if (!mockMode) {
+    return crypto.randomUUID();
+  } else {
+    mockCount++;
+    return `00000000-0000-4000-0000-${mockCount.toString().padStart(12, "0")}`;
+  }
+}
diff --git a/src/sing/utaformatixProject/toVoicevox.ts b/src/sing/utaformatixProject/toVoicevox.ts
index f3e2448d67..04a80a6244 100644
--- a/src/sing/utaformatixProject/toVoicevox.ts
+++ b/src/sing/utaformatixProject/toVoicevox.ts
@@ -4,6 +4,7 @@ import { DEFAULT_TPQN, createDefaultTrack } from "@/sing/domain";
 import { getDoremiFromNoteNumber } from "@/sing/viewHelper";
 import { NoteId } from "@/type/preload";
 import { Note, Tempo, TimeSignature, Track } from "@/store/type";
+import { uuid4 } from "@/helpers/random";
 
 /** UtaformatixのプロジェクトをVoicevoxの楽譜データに変換する */
 export const ufProjectToVoicevox = (project: UfProject): VoicevoxScore => {
@@ -72,7 +73,7 @@ export const ufProjectToVoicevox = (project: UfProject): VoicevoxScore => {
 
     const notes = trackNotes.map((value): Note => {
       return {
-        id: NoteId(crypto.randomUUID()),
+        id: NoteId(uuid4()),
         position: convertPosition(value.tickOn, projectTpqn, tpqn),
         duration: convertDuration(
           value.tickOn,
diff --git a/src/store/audio.ts b/src/store/audio.ts
index 343ae6e8f8..df75e2cf66 100644
--- a/src/store/audio.ts
+++ b/src/store/audio.ts
@@ -58,9 +58,10 @@ import { AudioQuery, AccentPhrase, Speaker, SpeakerInfo } from "@/openapi";
 import { base64ImageToUri, base64ToUri } from "@/helpers/base64Helper";
 import { getValueOrThrow, ResultError } from "@/type/result";
 import { generateWriteErrorMessage } from "@/helpers/fileHelper";
+import { uuid4 } from "@/helpers/random";
 
 function generateAudioKey() {
-  return AudioKey(crypto.randomUUID());
+  return AudioKey(uuid4());
 }
 
 function parseTextFile(
diff --git a/src/store/command.ts b/src/store/command.ts
index 9af3013e82..2842ee4185 100644
--- a/src/store/command.ts
+++ b/src/store/command.ts
@@ -10,6 +10,7 @@ import {
   MutationTree,
 } from "@/store/vuex";
 import { CommandId, EditorType } from "@/type/preload";
+import { uuid4 } from "@/helpers/random";
 
 enablePatches();
 enableMapSet();
@@ -67,7 +68,7 @@ const recordPatches =
       (draft: S) => recipe(draft, payload),
     );
     return {
-      id: CommandId(crypto.randomUUID()),
+      id: CommandId(uuid4()),
       redoPatches: doPatches,
       undoPatches: undoPatches,
     };
diff --git a/src/store/preset.ts b/src/store/preset.ts
index 7ceaa9ccf9..a4981632f9 100644
--- a/src/store/preset.ts
+++ b/src/store/preset.ts
@@ -1,4 +1,5 @@
 import { createPartialStore } from "./vuex";
+import { uuid4 } from "@/helpers/random";
 import { PresetStoreState, PresetStoreTypes, State } from "@/store/type";
 import { Preset, PresetKey, Voice, VoiceId } from "@/type/preload";
 
@@ -181,7 +182,7 @@ export const presetStore = createPartialStore<PresetStoreTypes>({
 
   ADD_PRESET: {
     async action(context, { presetData }: { presetData: Preset }) {
-      const newKey = PresetKey(crypto.randomUUID());
+      const newKey = PresetKey(uuid4());
       const newPresetItems = {
         ...context.state.presetItems,
         [newKey]: presetData,
diff --git a/src/store/singing.ts b/src/store/singing.ts
index ba738ddc3e..fbc4a2896e 100644
--- a/src/store/singing.ts
+++ b/src/store/singing.ts
@@ -85,6 +85,7 @@ import { createLogger } from "@/domain/frontend/log";
 import { noteSchema } from "@/domain/project/schema";
 import { getOrThrow } from "@/helpers/mapHelper";
 import { ufProjectToVoicevox } from "@/sing/utaformatixProject/toVoicevox";
+import { uuid4 } from "@/helpers/random";
 
 const logger = createLogger("store/singing");
 
@@ -1724,7 +1725,7 @@ export const singingStore = createPartialStore<SingingStoreTypes>({
         const track = tracks[trackIndex];
         const notes = track.notes.map((note) => ({
           ...note,
-          id: NoteId(crypto.randomUUID()),
+          id: NoteId(uuid4()),
         }));
 
         if (tpqn !== state.tpqn) {
@@ -2144,7 +2145,7 @@ export const singingStore = createPartialStore<SingingStoreTypes>({
         const quantizedPastePos =
           Math.round(pasteOriginPos / snapTicks) * snapTicks;
         return {
-          id: NoteId(crypto.randomUUID()),
+          id: NoteId(uuid4()),
           position: quantizedPastePos,
           duration: Number(note.duration),
           noteNumber: Number(note.noteNumber),
diff --git a/tests/unit/lib/selectPriorPhrase.spec.ts b/tests/unit/lib/selectPriorPhrase.spec.ts
index 4f8b2e2580..cebfdcaca6 100644
--- a/tests/unit/lib/selectPriorPhrase.spec.ts
+++ b/tests/unit/lib/selectPriorPhrase.spec.ts
@@ -7,6 +7,7 @@ import {
 } from "@/store/type";
 import { DEFAULT_TPQN, selectPriorPhrase } from "@/sing/domain";
 import { NoteId } from "@/type/preload";
+import { uuid4 } from "@/helpers/random";
 
 const createPhrase = (
   firstRestDuration: number,
@@ -18,7 +19,7 @@ const createPhrase = (
     firstRestDuration: firstRestDuration * DEFAULT_TPQN,
     notes: [
       {
-        id: NoteId(crypto.randomUUID()),
+        id: NoteId(uuid4()),
         position: start * DEFAULT_TPQN,
         duration: (end - start) * DEFAULT_TPQN,
         noteNumber: 60,
diff --git a/tests/unit/lib/utaformatixProject/export.spec.ts b/tests/unit/lib/utaformatixProject/export.spec.ts
index 1fad3469b5..5193905dc7 100644
--- a/tests/unit/lib/utaformatixProject/export.spec.ts
+++ b/tests/unit/lib/utaformatixProject/export.spec.ts
@@ -6,8 +6,9 @@ import {
   createDefaultTrack,
 } from "@/sing/domain";
 import { NoteId } from "@/type/preload";
+import { uuid4 } from "@/helpers/random";
 
-const createNoteId = () => NoteId(crypto.randomUUID());
+const createNoteId = () => NoteId(uuid4());
 
 it("トラックを変換できる", async () => {
   const track = createDefaultTrack();
diff --git a/tests/unit/store/__snapshots__/command.spec.ts.snap b/tests/unit/store/__snapshots__/command.spec.ts.snap
new file mode 100644
index 0000000000..6d2a116d0c
--- /dev/null
+++ b/tests/unit/store/__snapshots__/command.spec.ts.snap
@@ -0,0 +1,41 @@
+// Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
+
+exports[`コマンド実行で履歴が作られる 1`] = `
+{
+  "audioKeys": [
+    "00000000-0000-4000-0000-000000000001",
+  ],
+  "redoCommands": {
+    "song": [],
+    "talk": [],
+  },
+  "undoCommands": {
+    "song": [],
+    "talk": [
+      {
+        "id": "00000000-0000-4000-0000-000000000002",
+        "redoPatches": [
+          {
+            "op": "replace",
+            "path": [
+              "audioKeys",
+            ],
+            "value": [
+              "00000000-0000-4000-0000-000000000001",
+            ],
+          },
+        ],
+        "undoPatches": [
+          {
+            "op": "replace",
+            "path": [
+              "audioKeys",
+            ],
+            "value": [],
+          },
+        ],
+      },
+    ],
+  },
+}
+`;
diff --git a/tests/unit/store/command.spec.ts b/tests/unit/store/command.spec.ts
new file mode 100644
index 0000000000..4ee14a1068
--- /dev/null
+++ b/tests/unit/store/command.spec.ts
@@ -0,0 +1,19 @@
+import { toRaw } from "vue";
+import { store } from "@/store";
+import { AudioKey } from "@/type/preload";
+import { resetMockMode, uuid4 } from "@/helpers/random";
+
+const initialState = structuredClone(toRaw(store.state));
+beforeEach(() => {
+  store.replaceState(initialState);
+
+  resetMockMode();
+});
+
+test("コマンド実行で履歴が作られる", async () => {
+  await store.dispatch("COMMAND_SET_AUDIO_KEYS", {
+    audioKeys: [AudioKey(uuid4())],
+  });
+  const { audioKeys, redoCommands, undoCommands } = store.state;
+  expect({ audioKeys, redoCommands, undoCommands }).toMatchSnapshot();
+});
diff --git a/tests/unit/store/utility.spec.ts b/tests/unit/store/utility.spec.ts
index c4a8907dc9..cb6430de9e 100644
--- a/tests/unit/store/utility.spec.ts
+++ b/tests/unit/store/utility.spec.ts
@@ -22,6 +22,7 @@ import {
   isOnCommandOrCtrlKeyDown,
   filterCharacterInfosByStyleType,
 } from "@/store/utility";
+import { uuid4 } from "@/helpers/random";
 
 function createDummyMora(text: string): Mora {
   return {
@@ -305,13 +306,13 @@ describe("filterCharacterInfosByStyleType", () => {
   const createCharacterInfo = (
     styleTypes: (undefined | "talk" | "frame_decode" | "sing")[],
   ): CharacterInfo => {
-    const engineId = EngineId(crypto.randomUUID());
+    const engineId = EngineId(uuid4());
     return {
       portraitPath: "path/to/portrait",
       metas: {
         policy: "policy",
         speakerName: "speakerName",
-        speakerUuid: SpeakerId(crypto.randomUUID()),
+        speakerUuid: SpeakerId(uuid4()),
         styles: styleTypes.map((styleType) => ({
           styleType,
           styleName: "styleName",